This application relates generally to the field of retractors for use in seat belt assemblies for restraining occupants. More specifically, this application relates to a retractor having an improved coupling that is configured to operatively connect a seat belt (e.g., a webbing) to a spool. The retractor may be used in a motorized seat belt (MSB) system.
Some vehicles may be equipped with a motorized seat belt (MSB) system. The MSB system is equipped with a motor driven retractor. The system may alert the driver to potential dangers through the movement of the webbing. When a vehicle sensor, such as the car's radar device, mounted in the front portion of the car, detects a potential hazard (which includes, for example, combining the distance from the car in front, the relative speed of the car, and other information), the MSB system operates to warn the driver by lightly pulling two or three times on the webbing (accomplished by operating the motor to drive a spool in a retraction direction). When a collision is unavoidable, the MSB may automatically retract the webbing to eliminate any slack between the passenger and the seat belt.
However, when the motor of the MSB is directly coupled to the spool, the cycling of the MSB may fatigue features and components of the retractor utilized in pretensioning the seat belt webbing through the torsion bar. Fatigue to these features and components may cause the retractor to under-perform or shift into an energy management mode prematurely.